/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.webmonitor.handlers.utils;

import org.apache.flink.annotation.VisibleForTesting;
import org.apache.flink.api.common.JobID;
import org.apache.flink.client.program.PackagedProgram;
import org.apache.flink.client.program.PackagedProgramUtils;
import org.apache.flink.client.program.ProgramInvocationException;
import org.apache.flink.configuration.ConfigUtils;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.CoreOptions;
import org.apache.flink.configuration.PipelineOptions;
import org.apache.flink.configuration.PipelineOptionsInternal;
import org.apache.flink.runtime.jobgraph.JobGraph;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.RestHandlerException;
import org.apache.flink.runtime.rest.messages.MessageParameters;
import org.apache.flink.runtime.webmonitor.handlers.EntryClassQueryParameter;
import org.apache.flink.runtime.webmonitor.handlers.JarIdPathParameter;
import org.apache.flink.runtime.webmonitor.handlers.JarRequestBody;
import org.apache.flink.runtime.webmonitor.handlers.ParallelismQueryParameter;
import org.apache.flink.runtime.webmonitor.handlers.ProgramArgQueryParameter;
import org.apache.flink.runtime.webmonitor.handlers.ProgramArgsQueryParameter;

import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;

import org.slf4j.Logger;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CompletionException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static org.apache.flink.runtime.rest.handler.util.HandlerRequestUtils.fromRequestBodyOrQueryParameter;
import static org.apache.flink.runtime.rest.handler.util.HandlerRequestUtils.getQueryParameter;
import static org.apache.flink.shaded.guava30.com.google.common.base.Strings.emptyToNull;
import static org.apache.flink.util.Preconditions.checkNotNull;

/**
 * Utils for jar handlers.
 *
 * @see org.apache.flink.runtime.webmonitor.handlers.JarRunHandler
 * @see org.apache.flink.runtime.webmonitor.handlers.JarPlanHandler
 */
public class JarHandlerUtils {

    /** Standard jar handler parameters parsed from request. */
    public static class JarHandlerContext {
        private final Path jarFile;
        private final String entryClass;
        private final List<String> programArgs;
        private final int parallelism;
        private final JobID jobId;

        private JarHandlerContext(
                Path jarFile,
                String entryClass,
                List<String> programArgs,
                int parallelism,
                JobID jobId) {
            this.jarFile = jarFile;
            this.entryClass = entryClass;
            this.programArgs = programArgs;
            this.parallelism = parallelism;
            this.jobId = jobId;
        }

        public static <R extends JarRequestBody> JarHandlerContext fromRequest(
                @Nonnull final HandlerRequest<R> request,
                @Nonnull final Path jarDir,
                @Nonnull final Logger log)
                throws RestHandlerException {
            final JarRequestBody requestBody = request.getRequestBody();

            final String pathParameter = request.getPathParameter(JarIdPathParameter.class);
            Path jarFile = jarDir.resolve(pathParameter);

            String entryClass =
                    fromRequestBodyOrQueryParameter(
                            emptyToNull(requestBody.getEntryClassName()),
                            () ->
                                    emptyToNull(
                                            getQueryParameter(
                                                    request, EntryClassQueryParameter.class)),
                            null,
                            log);

            List<String> programArgs = JarHandlerUtils.getProgramArgs(request, log);

            int parallelism =
                    fromRequestBodyOrQueryParameter(
                            requestBody.getParallelism(),
                            () -> getQueryParameter(request, ParallelismQueryParameter.class),
                            CoreOptions.DEFAULT_PARALLELISM.defaultValue(),
                            log);

            JobID jobId =
                    fromRequestBodyOrQueryParameter(
                            requestBody.getJobId(),
                            () -> null, // No support via query parameter
                            null, // Delegate default job ID to actual JobGraph generation
                            log);

            return new JarHandlerContext(jarFile, entryClass, programArgs, parallelism, jobId);
        }

        public void applyToConfiguration(final Configuration configuration) {
            checkNotNull(configuration);

            if (jobId != null) {
                configuration.set(
                        PipelineOptionsInternal.PIPELINE_FIXED_JOB_ID, jobId.toHexString());
            }
            configuration.set(CoreOptions.DEFAULT_PARALLELISM, parallelism);

            final PackagedProgram program = toPackagedProgram(configuration);
            ConfigUtils.encodeCollectionToConfig(
                    configuration,
                    PipelineOptions.JARS,
                    program.getJobJarAndDependencies(),
                    URL::toString);
            ConfigUtils.encodeCollectionToConfig(
                    configuration,
                    PipelineOptions.CLASSPATHS,
                    program.getClasspaths(),
                    URL::toString);
        }

        public JobGraph toJobGraph(
                PackagedProgram packagedProgram,
                Configuration configuration,
                boolean suppressOutput) {
            try {
                return PackagedProgramUtils.createJobGraph(
                        packagedProgram, configuration, parallelism, jobId, suppressOutput);
            } catch (final ProgramInvocationException e) {
                throw new CompletionException(e);
            }
        }

        public PackagedProgram toPackagedProgram(Configuration configuration) {
            checkNotNull(configuration);

            if (!Files.exists(jarFile)) {
                throw new CompletionException(
                        new RestHandlerException(
                                String.format("Jar file %s does not exist", jarFile),
                                HttpResponseStatus.BAD_REQUEST));
            }

            try {
                return PackagedProgram.newBuilder()
                        .setJarFile(jarFile.toFile())
                        .setEntryPointClassName(entryClass)
                        .setConfiguration(configuration)
                        .setArguments(programArgs.toArray(new String[0]))
                        .build();
            } catch (final ProgramInvocationException e) {
                throw new CompletionException(e);
            }
        }
    }

    /** Parse program arguments in jar run or plan request. */
    private static <R extends JarRequestBody, M extends MessageParameters>
            List<String> getProgramArgs(HandlerRequest<R> request, Logger log)
                    throws RestHandlerException {
        JarRequestBody requestBody = request.getRequestBody();
        @SuppressWarnings("deprecation")
        List<String> programArgs =
                tokenizeArguments(
                        fromRequestBodyOrQueryParameter(
                                emptyToNull(requestBody.getProgramArguments()),
                                () -> getQueryParameter(request, ProgramArgsQueryParameter.class),
                                null,
                                log));
        List<String> programArgsList =
                fromRequestBodyOrQueryParameter(
                        requestBody.getProgramArgumentsList(),
                        () -> request.getQueryParameter(ProgramArgQueryParameter.class),
                        null,
                        log);
        if (!programArgsList.isEmpty()) {
            if (!programArgs.isEmpty()) {
                throw new RestHandlerException(
                        "Confusing request: programArgs and programArgsList are specified, please, use only programArgsList",
                        HttpResponseStatus.BAD_REQUEST);
            }
            return programArgsList;
        } else {
            return programArgs;
        }
    }

    private static final Pattern ARGUMENTS_TOKENIZE_PATTERN =
            Pattern.compile("([^\"\']\\S*|\".+?\"|\'.+?\')\\s*");

    /**
     * Takes program arguments as a single string, and splits them into a list of string.
     *
     * <pre>
     * tokenizeArguments("--foo bar")            = ["--foo" "bar"]
     * tokenizeArguments("--foo \"bar baz\"")    = ["--foo" "bar baz"]
     * tokenizeArguments("--foo 'bar baz'")      = ["--foo" "bar baz"]
     * tokenizeArguments(null)                   = []
     * </pre>
     *
     * <strong>WARNING: </strong>This method does not respect escaped quotes.
     */
    @VisibleForTesting
    static List<String> tokenizeArguments(@Nullable final String args) {
        if (args == null) {
            return Collections.emptyList();
        }
        final Matcher matcher = ARGUMENTS_TOKENIZE_PATTERN.matcher(args);
        final List<String> tokens = new ArrayList<>();
        while (matcher.find()) {
            tokens.add(matcher.group().trim().replace("\"", "").replace("\'", ""));
        }
        return tokens;
    }
}
